The invention relates to an internal combustion engine with direct fuel injection, which provides for a stratified combustion in a wide performance range and includes pistons which are movably disposed in cylinders and define combustion chambers limited by a cylinderhead wall. Injectors are mounted in the cylinderhead which inject fuel into the combustion chambers in cone-like patterns to form in the combustion chambers with the combustion air a fuel/air mixture which is ignited by a spark plug.
DE 43 24 642 A1 discloses such an internal combustion engine including a combustion chamber which is delimited by a piston disposed in a cylinder of the internal combustion engine and the inner wall of a cylinderhead. An injection nozzle of an injector injects fuel in a cone-like pattern into the combustion chamber where an ignitable fuel/air mixture is formed with the combustion air admitted to the combustion chamber. The mixture is ignited by a spark plug having electrodes which extend into the cone-shaped fuel spray pattern and between which a spark is generated. The electrodes are arranged adjacent the injection nozzle whereby a fuel-rich mixture is ignited such that stratified combustion is achieved depending on the engine load, and, as a result of a pressure and temperature increase resulting from the combustion of the fuel-rich mixture portion, the fuel-lean mixture in the remainder of the combustion chamber is combusted. The electrodes are wetted by the fuel injected into the combustion chamber so that, over a period of time, carbon deposits may form on the electrodes whereby the development of a spark may be prevented. Furthermore, the electrodes must be relatively long in order to facilitate ignition of the mixture adjacent the fuel injection nozzle. As a result, depending on the engine load, either knocking may occur by excessively heated electrodes in the area where they are exposed to the fuel or carbon deposits may form on the electrodes because of cooling of the electrodes by their exposure to the fuel.
It is the principal object of the present invention to provide an internal combustion engine with direct fuel injection which will maintain optimal operating conditions over a long period of time.